‘Explain how lichens are environmental indicators’

Due to lichens being sensitive to environmental changes and disturbances it is a good environmental indicator. An environmental indicator is something which tell us of what’s happening in the environment, for example lichens reacting with air pollution. If they are exposed to air pollution, especially bushy ones, they can stop growing and die. This means that scientists may use them to study pollution levels in different areas by observing how lichens cope.